"Blot off excess, use either methylated spirits or a commercial stain remover. Use a syphon containing soda water, spray over carpet, then blot dry before using the methylated spirits. Follow up with a carpet shampoo".
Oh! Isn't it just awful when this happens... This happened to me once..I found the best thing to do was ONLY DRINK WHITE ALCOHOLIC DRINKS or...splash out on real red wine (this can be removed quite easily) And if all else fails.... place a small settee over the offending stain! X
If all else fails, getting someone in should only be around �25, I had to when someone trod tar in to my carpet and the first solution I tried made it worse!